JPH0729875Y2 - Backrest locking device in chair - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a locking device for a backrest in a chair for office work or the like, which allows the backrest to tilt rearward against the elasticity of a spring body. .

[Problems to be solved by conventional technologies and devices]

The locking device for the backrest in office chairs is
Generally, a backrest support with a backrest attached is attached to the rear of the seat so that it can be tilted rearward, and a coil spring is inserted between the backrest support and the seat to elastically move the backrest backward. Backrest, or by attaching a backrest to the backrest support rod fixed to the rear end of the seat so that it can be tilted rearward, and inserting a coil spring between the backrest and the backrest support rod. Is said to be elastically supported.

However, as in the conventional case, a spring such as a coil spring whose spring constant (hardness) does not change is used as a spring body for supporting the rearward tilting of the backrest, in other words, a spring body with a constant spring constant. In the case of supporting the back tilting of the backrest, when the person sitting on the chair leans against the backrest, the angle of the backrest tilting backward is small for a light weight person and for a heavy weight person. Therefore, there is a problem that one chair cannot give the same sitting comfort to persons having different weights.

That is, if the spring body for the backrest is set to have a small spring constant according to a person with a light weight, when a person with a light weight leans back, even if the backrest leans backward at an appropriate angle, the body with a heavy weight is heavy. If a person leans back,
The backrest leans excessively. On the other hand, if the spring body for the backrest is set to have a large spring constant according to a person with a heavy weight, when a person with a heavy weight leans back, even if the backrest leans backward at an appropriate angle, When a light person leans back, the locking function becomes incomplete, so that the backrest leans back only at a slight angle, so regardless of the weight of the person sitting on the chair, an appropriate locking function can be achieved. It was not possible to secure it.

An object of the present invention is to provide a backrest locking device that solves this problem.

[Means for Solving the Problems]

To achieve this object, the present invention attaches a seat to a support mechanism attached to the upper part of a leg of a chair through a weight-sensing mechanism so that the seat can be tilted backward or moved downward depending on the load on the seat. At the same time, a backrest support to which a backrest is attached is attached so as to be able to tilt rearwardly, and a beam-type spring body that elastically supports the rearward tilting of the backrest support via a slider is provided on the backrest support or the support mechanism. On the other hand, a link mechanism provided with one or a plurality of link rods is provided between the seat body and the support mechanism so that the link rods are rotated by the rearward tilting or lowering movement of the seat body. The slider is interlockingly connected to the link mechanism so that the slider moves in a direction in which the spring constant of the spring body is increased by tilting or lowering the seat body rearward.

[Function and effect of device]

In this configuration, when a person sits on the chair, the seat body tilts backward or descends according to the weight of the person sitting on the seat body through the weight-sensing mechanism, and when the seat body tilts backward or descends, In response to this, the link rod of the link mechanism rotates, and the slider is forcibly moved in the direction of increasing the spring constant of the beam-shaped spring body in association with the rotation of the link rod.

Then, when a person sitting in a chair leans against the backrest, the load due to the rearward tilting of the backrest acts on the beam-shaped spring body via the slider and resists the elasticity of the beam-shaped spring body. The backrest tilts backward while flexing and deforming. In other words, the backrest tilts backward against the elasticity of the beam-shaped spring body,
A locking function for the backrest is added.

In that case, the tilting angle or the descending amount of the seat body changes according to the weight of the person sitting on the chair by the weight-sensitive mechanism, so that the rotation angle of the link rod in the link mechanism also varies depending on the person sitting on the chair. The amount of movement of the slider that moves through the link mechanism, that is, the supporting span of the load on the spring body changes according to the weight of the person sitting on the chair, so that the backrest changes. The rate at which the spring constant of the spring body increases (the spring body becomes harder) changes in proportion to the light weight of the person sitting on the chair.

In other words, when a person with a light weight sits down, the slider moves only a small amount and the spring constant of the spring body does not increase so much, so when a person with a light weight leans against the backrest, the backrest is When a heavy person sits down, on the other hand, when a heavy person sits, the slider moves a lot and the spring constant of the spring body increases. Even if you lean against the backrest, you will still lean back at an appropriate angle.

Therefore, according to the present invention, when the spring constant of the spring body that supports the rearward tilting of the backrest is automatically adjusted according to the weight of the person sitting on the chair, and the light weight person leans on the backrest. However, even if a heavy person leans against the backrest, the backrest can be kept at an appropriate angle, so that a single chair gives a good sitting comfort regardless of the weight. It has the effect that

〔Example〕

An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 to FIG. 6 show the first embodiment. In the drawings, reference numeral 1 is a leg of a chair, and reference numeral 2 is the leg. Each of the support mechanisms is attached to the upper end of the leg 1, and the support mechanism 2 is composed of a fixed frame body 3 that is fitted to the upper end of the leg body 1 and has a generally U-shape in a front cross-sectional view.

Reference numeral 4 indicates a seat body formed by tensioning a cushion material 6 on the upper surface of the seat plate 5, and a seat receiving body 7 having a downward U-shaped cross section is fixed to the lower surface of the seat plate 5 of the seat body 4, The front end portions of the left and right side plates 7a of the seat receiving body 7 are connected to the left and right side plates of the fixed frame body 3.
The pivot member 8 is pivotally attached between the front end portions of 3a, so that the seat body 4
Is configured to be tiltable rearward about the support shaft 8.

Then, the tip end portion of the seat receiving body 7 and the tip end portion of the fixed frame body 3 are each formed in a curved shape in a side sectional view, and the inner surfaces of the curved tip end portions 7b of the seat receiving body 7 and the fixed frame body 3 are formed. At a position with the inner surface of the curved distal end portion 3b in, the seat body 4 is tilted rearward according to the weight of the person sitting on the seat body 3 as an example of a weight-sensing mechanism having a substantially lateral U-shaped cross section. Sensitive leaf spring 9
The curved tip portions 7b, 3 of the seat receiving body 7 and the fixed frame body 3.
It is arranged so as to extend along the inner surface of b, and the lower end of the body weight application leaf spring 9 is locked to the bottom surface of the fixed frame body 3 by a locking member 10.

The forward inclination of the seat receiving body 7 is regulated by bringing the front end surface of the curved front end portion 7b of the seat receiving body 7 into contact with the front end surface of the curved front end portion 3b of the fixed frame body 3. .

Reference numeral 11 denotes a backrest support body disposed between the fixed frame body 3 and the seat support body 7. The backrest support body 11 is formed in a substantially downward U-shaped cross section, and the rear end portion thereof faces upward. The backrest mounting rod 12 extending integrally with the backrest mounting rod 12 and the backrest 14 with the cushion 13 attached to the backrest mounting rod 12 while the front end portions of the left and right side plates 11a of the backrest support 11 are rotated around the spindle 8. The backrest support 11 and the backrest 14 are configured to be tilted rearward about the support shaft 8 by being movably fitted.

A backrest is provided between the fixed frame body 3 and the backrest support body 11.
As an example of a beam-type spring body that elastically supports rearward tilting 14, a spring body 15 formed of a leaf spring is arranged so as to extend along the front-back direction of the chair, and the spring body 15 is The base end (front end) is fastened to the tip of the upper surface plate 11b of the backrest support 11 with a bolt 16 to form a cantilever, while the tip of the spring body 15 serves as the bottom plate of the fixed frame body 3. The slider 17 is formed so as to extend substantially in parallel, and a left and right longitudinal slider 17 is inserted between the tip of the spring body 15 and the bottom plate of the fixed frame body 3, and the slider 17 is seated by a link mechanism 18. The receiver 7 is configured to move forward in association with the rearward tilting.

The link mechanism 18 includes a pair of inclined left and right first link rods 20 whose rear ends are rotatably pivoted to the rear ends of the left and right side plates 7a of the seat receiving body 7 by pins 19. The left and right first link rods 20 are composed of a pair of left and right second link rods 22 pivotally attached to the front ends thereof by a pin 21, and the front ends of the left and right second link rods 22 are connected to each other. Left and right laterally long guide rollers 23 are rotatably fitted on the connecting pins 21, while the fixed frame 3
An inclined guide member 24 that extends obliquely upward toward the front of the chair is fixed to the bottom surface of the chair, the guide roller 23 is abutted on the upper surface of the inclined guide member 24, and further, the left and right second link rods 22 are At the rear end, the slider 17 is rotatably supported by a pin 25.

The backrest support 11 includes the seat support 7 and the fixed frame 3
Since the seat receiving body 7 functions as a stopper and does not tilt forward more than a certain angle because it is disposed between and, means for preventing the seat back support 11 from tilting forward may be separately provided. Code 8
Each of a and 21a indicates a color.

With the above configuration, when a person sits on the chair, the seat receiving body 7 is
It tilts rearward against the leaf spring 9 for applying a feeling of weight, and in conjunction with the rearward tilting of the seat receiving body 7, as shown by the alternate long and short dash line in FIG. Although rotating, since the guide roller 23 fitted to the pin 21 connecting the ends of the left and right link rods 20 is in contact with the upper surface of the inclined guide member 24, the front ends of the left and right first link rods 20 are Move horizontally toward the front of the chair by a distance l.

Then, the slider 17 moves toward the front of the chair via the left and right second link rods 22 so that the support span L of the spring body 15 becomes small, in other words, the spring constant of the spring body 15 is large. When a person sitting on a chair leans against the backrest 14, the backrest support 11 is elastically supported by the spring body 15 as shown by the alternate long and short dash line in FIGS. 1 and 6. , A locking function for back tilting of the backrest 14 is added.

In this case, since the point of action of the load of the seat receiver 7 on the body weight application leaf spring 9 is substantially constant when the seat receiver 7 rotates, the backward tilt angle of the seat receiver 7 is set to Since it increases in proportion to the weight of the person who wears it, the left and right first link rods 20
The rotation angle also changes in proportion to the weight of the person sitting on the chair, and the front ends of the left and right first link rods 20 move horizontally, in other words, the slider 17 moves in the longitudinal direction of the spring body 15. The distance l moving along will also change in proportion to the weight of the person sitting on the chair.

Therefore, when a person with a light weight sits down, the moving distance l of the slider 17 is small and the load supporting span L of the spring body 15 does not become so small that the spring body 15 acts as a soft spring. When a light weight person leans against the backrest 14, the backrest 14 tilts backward by an appropriate angle to ensure an appropriate rocking function, while when a heavy person sits, the slider 17 Distance traveled
Is large and the supporting span L of the load in the spring body 15 is small, the spring body 15 acts as a hard spring. Therefore, when a heavy person leans against the backrest 14, the backrest 14 rotates. The angle does not become excessively large, and a proper locking function can be secured.

The guide rollers 23 may directly contact the bottom surface of the fixed frame body 3 without providing the inclined guide bodies 24 for the left and right first link rods 20, but if the inclined guide bodies 24 are provided, the first link Since the rotation angle of the rod 20 is amplified, even if the change in the rearward tilt angle of the seat receiving body 7 is small, the supporting span L of the load on the spring body 15 changes significantly, so that the spring constant of the spring body 15 is reduced. It has an advantage that the sensitivity of adjustment can be improved.

7 to 12 show a second embodiment of the present invention. The embodiment and the first embodiment are different from the support mechanism 2 in FIG.
And the weight-sensitive mechanism, and the link mechanism 18 and the slider have different configurations.

That is, in the support mechanism 2 in the embodiment, the forward opening box type fixing member 26 fitted to the upper end of the leg 1 and the left and right side plates 26a of the fixing frame 26 with the horizontal pin 27 at the base end portion. It is composed of an arm member 28 having a U-shaped cross section that is pivotally rotatably attached. One end of a leaf spring 29 is fixed to the rear end of the arm member 28 with a bolt 30 or the like. The end of the fixing member 26
By contacting the lower surface of the upper plate 26b, the arm member 28 and the seat body 4 can be tilted forward by a slight angle against the elasticity of the leaf spring 29.

In addition, a weight-sensing applied leaf spring as an example of a weight-sensing mechanism is provided at the left and right ends of the front end of the arm member 28.
The lower end of 31 is fixed with bolts 32, and these left and right body weight application leaf springs 31 are directed between the left and right side plates 28a of the arm member 28 and the side surfaces of the backrest support body 11 toward the lower surface of the seat receiving body 7. The seat support 7 extends obliquely upward and resists the elasticity of the left and right body weight application leaf springs 31 so that the seat support 7 can be tilted rearward about the support shaft 8.

Then, by the same means as in the first embodiment, a link mechanism 18 composed of both left and right first link rods 20 and left and right second link rods 22 is provided, and between the rear ends of the left and right second link rods 22. In addition, a support roller 33 that contacts the lower surface of the spring body 15 fixed to the backrest support body 11 and a support roller 34 that contacts the upper surface of the upper surface plate 26a of the fixed frame body 26 by pins 35 and 36, respectively. It is rotatably supported. That is, the slider is divided into two upper and lower support rollers 33, 34.

In this embodiment, the first link rod 20 and the second link rod 20
Although the connecting portion with 22 is in a free state without contacting with the arm member 28 or the fixed frame body 26, it is brought into contact with the arm member 28 or the fixed frame body 26 as in the first embodiment. Thus, the rotation of the left and right first link rods 20 may be forcibly guided.

Reference numeral 28b is a stopper that restricts the forward leaning of the seat support 7 and the backrest support 11.

The operation of the second embodiment is similar to that of the first embodiment, and the rearward inclination angle of the seat support 7 changes in proportion to the weight of the person sitting on the seat 4, and the spring body 15 and Since the amount of movement of the support rollers 33, 34 with respect to the fixed frame body 26 is proportional to the weight of the person sitting on the chair, the spring constant of the spring body 15 is adjusted according to the weight of the person sitting on the chair. Become.

If the slider is divided into the support roller 33 for the spring body 15 and the support roller 34 for the fixed frame body 26 as in the second embodiment, the movement of the second link rod 22 becomes smooth, and the spring There is an advantage that the spring constant in the body 16 can be adjusted smoothly.

In the above two embodiments, the slider was directly attached to the link mechanism.
Instead of connecting the second link rod 22 to the first link rod 20, the link mechanism and the slider are indirectly connected by connecting the tips of the left and right first link rods 20 and the slider 17 with a wire. (However, if the link mechanism and slider are connected by wire in this way, the slider will return to its original position even if the link mechanism is restored and rotated. Since it cannot be returned, a means such as a spring is required to urge the slider to return to the retracted state).

Further, the form of the link mechanism is not limited to the embodiment, and, for example, the slider 17 is directly connected to the lower ends of the left and right first link rods 20, or the seat support 7 and the support mechanism 2 are formed in a pantograph shape. By connecting with a link mechanism, the connecting portion of the link rod and the slider in the pantograph-like link mechanism are connected with a connecting rod or a wire, and the seat rod 7 is tilted rearward to connect the link rod with the link mechanism. The slider may be forcibly moved by utilizing the fact that the section moves in the horizontal direction.

Further, the seat body is not limited to be attached to the support mechanism so that it can be tilted rearward, and may be attached so as to be movable downward. The weight-sensing mechanism to be changed by the above is not limited to the leaf spring as in the embodiment, but other forms of spring means such as a coil spring or a torsion spring may be used.

Furthermore, the mounting form of the spring body to the backrest support body is not limited to the cantilever shape, but may be a support shape at both ends. Furthermore, a plate-shaped or rod-shaped spring body is used as the spring body. When a cantilever is provided, one or both of the width dimension and the thickness dimension of the spring body,
It becomes smaller toward the tip of the spring body, that is,
The spring body may be formed so that the quadratic coefficient of section becomes smaller toward the tip.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a vertical sectional side view of a chair according to the first embodiment, which is a sectional view taken along line II of FIG. 2, and FIG. 2 is a plan view taken along line II-II of FIG. Sectional view, Fig. 3 is II of Fig. 1.
FIG. 4 is a sectional view taken along line IV-IV of FIG. 1, FIG. 5 is a sectional view taken along line VV of FIG. 1, and FIG. 6 is a schematic sectional view showing the action. FIG. 8 is a vertical sectional side view of the chair in the second embodiment, which is a sectional view taken along line VII-VII in FIG. 9, and FIG. 8 is VI in FIG.
II-VIII sectional view, FIG. 9 is a plan view taken along line IX-IX of FIG.
10 is a sectional view taken along line XX in FIG. 7, and FIG. 11 is XI in FIG.
FIG. 12 is a schematic cross-sectional view taken along the line-XI of FIG. 1 ... Legs, 2 ... Support mechanism, 3,26 ... Fixed frame, 4 ...
… Seat body, 7 …… Seat receiving body, 18 …… Spindle, 9,31 …… Sheet weight application leaf spring, 11 …… Backrest support, 14 …… Backrest, 15
...... Spring body, 17 …… Slider, 18 …… Link mechanism, 20 ……
1st link rod, 22 …… Second link rod, 24 …… Inclined guide body, 33,34 …… Supporting rollers.

Claims (1)

[Scope of utility model registration request] 1. A seat is attached to a support mechanism attached to an upper part of a leg of a chair through a weight-sensing mechanism so that the seat can be tilted backward or lowered according to a load on the seat, and a backrest is attached. A backrest support is attached so as to be tiltable rearward, and a beam-type spring body that elastically supports the backrest support rearward tilting through a slider is provided on the backrest support or the support mechanism, while the seat body is provided. And a support mechanism, a link mechanism having one or a plurality of link rods is provided so that the link rod can be rotated by the rearward tilting or lowering movement of the seat body. A rocking device for a backrest in a chair, characterized in that the slider is interlockingly connected so that the slider moves in a direction in which the spring constant of the spring body is increased by rearward tilting or lowering of the seat body.